Why is my car slower?

[Bentcrank]

I have a 90 Tallon TSI. I installed this weekend

SAFC2 (stock settings till I get a reliable wideband)
Auto lite plugs ( 1 heat range colder )
2 1/2 from DP back (no cat)
MBC (12PSI)
255 LPH pump
Open air box w/ K+N
ApexI auto timer

I would think that after these mods the car would be the same or at least a little more responsive. Its actually SLOWER

I'm going to change the plug wires to see if it helps but I doubt thats the issue. The car just accelerates very slowly. When boost comes on its very faint mostly in 3rd gear and lacks the oomph it once had. I have no leaks that I could find and I haven't uped the boost just yet until I eliminate the problem.

If this keeps up Im buying another 5.0

 

[project94tsi]

you probably need an AFPR because that 255 fuel pump is over running your stock one causing you to run rich

 

[Bentcrank]

you probably need an AFPR because that 255 fuel pump is over running your stock one causing you to run rich

Thats what I was thinking but I wasn't sure if the stock one could regulate the 255 or not. I was going to up the boost to 15PSI and try to tune with the SAFC but I voted no on that. I like my engine intact for the time being.


Next purchases

550s
FPR
FP guage

 

[oldman]

I have a 90 Tallon TSI. I installed this weekend

SAFC2 (stock settings till I get a reliable wideband)
Auto lite plugs ( 1 heat range colder )
2 1/2 from DP back (no cat)
MBC (12PSI)
255 LPH pump
Open air box w/ K+N
ApexI auto timer

I would think that after these mods the car would be the same or at least a little more responsive. Its actually SLOWER

I'm going to change the plug wires to see if it helps but I doubt thats the issue. The car just accelerates very slowly. When boost comes on its very faint mostly in 3rd gear and lacks the oomph it once had. I have no leaks that I could find and I haven't uped the boost just yet until I eliminate the problem.

If this keeps up Im buying another 5.0

Are you using your butt dyno to determine which is faster? The safc2 is a little early for you, you really don't need the safc until you change the injector size. Check the fuel pressure if you can, the 255 could be over running your stock fuel pressure regulator (running rich). Try using NGK bpr7es next time you change them. Can you be a little more detailed on the boost issue, sounds like you have boost leak. Did you do a real boost leak test? Good luck.

 

[oldman]

you probably need an AFPR because that 255 fuel pump is over running your stock one causing you to run rich

You kids type too fast for me.

 

[mavisky]

You are definitely over running your fuel pressure regulator at low boost with that 255. Most cars with a re-wired stock pump are capable of running up to 15 psi, so don't be afraid to turn it up a notch. With 510's, a 180lph pump, maft, and afpr i'm able to run 20 psi daily on 93-94 octane.